From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752698AbcFEKWu (ORCPT ); Sun, 5 Jun 2016 06:22:50 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21908 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752637AbcFEKWq (ORCPT ); Sun, 5 Jun 2016 06:22:46 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Ivanov , Dmitry Ivanov , Johannes Berg , Willy Tarreau Subject: [PATCH 3.10 086/143] nl80211: check netlink protocol in socket release notification Date: Sun, 5 Jun 2016 12:19:49 +0200 Message-Id: <1465122046-9645-87-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dmitry Ivanov commit 8f815cdde3e550e10c2736990d791f60c2ce43eb upstream. A non-privileged user can create a netlink socket with the same port_id as used by an existing open nl80211 netlink socket (e.g. as used by a hostapd process) with a different protocol number. Closing this socket will then lead to the notification going to nl80211's socket release notification handler, and possibly cause an action such as removing a virtual interface. Fix this issue by checking that the netlink protocol is NETLINK_GENERIC. Since generic netlink has no notifier chain of its own, we can't fix the problem more generically. Fixes: 026331c4d9b5 ("cfg80211/mac80211: allow registering for and sending action frames") Cc: stable@vger.kernel.org Signed-off-by: Dmitry Ivanov [rewrite commit message] Signed-off-by: Johannes Berg Signed-off-by: Willy Tarreau --- net/wireless/nl80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 90a0e55..dd3dbed 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -10685,7 +10685,7 @@ static int nl80211_netlink_notify(struct notifier_block * nb, struct wireless_dev *wdev; struct cfg80211_beacon_registration *reg, *tmp; - if (state != NETLINK_URELEASE) + if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC) return NOTIFY_DONE; rcu_read_lock(); -- 2.8.0.rc2.1.gbe9624a